c++中谓词与适配器

#include <iostream>
#include <vector>
#include<algorithm>

using namespace std;

class great_20{
public:
    bool operator()(int val){
        return val>20;
    }

};
bool greater_20(int val){
    return val>20;
}
//一元谓词
void test01(){
    vector<int> vec;
    vec.push_back(10);
    vec.push_back(50);
    vec.push_back(20);
    vec.push_back(80);
    for_each(vec.begin(),vec.end(),[](int val){cout<<val<<"  ";});
    cout<<endl;
    vector<int>::iterator ret;
    ret=find_if(vec.begin(),vec.end(),greater_20);
    //普通函数
    if(ret==vec.end()){cout<<"未找到"<<endl;}else{cout<<"找到"<<*ret<<endl;}
    //仿函数
    vector<int>::iterator v_i=find_if(vec.begin(),vec.end(),great_20());
    if(v_i==vec.end()){cout<<"未找到"<<endl;}else{cout<<"找到"<<*v_i<<endl;}

}
//二元谓词
bool great_dayu(int val1,int val2){
    return val1>val2;
}
class great_class{
public:
    bool operator()(int val1,int val2){
        return val1>val2;
    }

};
void test02(){
    vector<int> vec;
    vec.push_back(10);
    vec.push_back(50);
    vec.push_back(20);
    vec.push_back(80);
    for_each(vec.begin(),vec.end(),[](int val){cout<<val<<"  ";});
    cout<<endl;
    sort(vec.begin(),vec.end(),great_dayu);
    cout<<"排序后："<<endl;
    for_each(vec.begin(),vec.end(),[](int val){cout<<val<<"  ";});
    cout<<endl;
    cout<<"仿函数排序："<<endl;
    sort(vec.begin(),vec.end(),great_class());
    for_each(vec.begin(),vec.end(),[](int val){cout<<val<<"  ";});
    cout<<endl;
    //内建函数对象
    cout<<"内建函数对象:"<<endl;
    sort(vec.begin(),vec.end(),greater<int>());
    for_each(vec.begin(),vec.end(),[](int val){cout<<val<<"  ";});
    cout<<endl;
    sort(vec.begin(),vec.end(),less<int>());
    for_each(vec.begin(),vec.end(),[](int val){cout<<val<<"  ";});
    cout<<endl;
    plus<int> p;
    cout<<p(10,20)<<endl;



}
//适配器(仿函数)
class print_vector:public binary_function<int,int,void>{
public:
    void operator()(int val,int temp)const{
        cout<<"val:"<<val<<" "<<"temp"<<temp<<" "<<"val+temp" <<val+temp<<" "<<endl;
    }
};
void test03(){
    vector<int> vec;
    vec.push_back(10);
    vec.push_back(50);
    vec.push_back(20);
    vec.push_back(80);
    for_each(vec.begin(),vec.end(),[](int val){cout<<val<<"  ";});
    cout<<endl;

    cout<<"适配器：bind2nd"<<endl;
    for_each(vec.begin(),vec.end(),bind2nd(print_vector(),100));
    cout<<endl;

    cout<<"适配器：bind1st"<<endl;
    for_each(vec.begin(),vec.end(),bind1st(print_vector(),100));
    cout<<endl;

}
//适配器（普通函数）
void plus_temp(int val,int temp){
    cout<<val+temp<<endl;
}
void test05(){
    vector<int> vec;
    vec.push_back(10);
    vec.push_back(50);
    vec.push_back(20);
    vec.push_back(80);
    for_each(vec.begin(),vec.end(),[](int val){cout<<val<<"  ";});
    cout<<endl;
    for_each(vec.begin(),vec.end(),bind2nd(ptr_fun(plus_temp),100));
    cout<<endl;
}

//成员函数适配器
class person{
public:
    string name;
    int age;
    person(string name,int age){
        this->name=name;
        this->age=age;

    }
    void print_person(){
        cout<<"name: "<<this->name<<" "<<"age:"<<this->age<<endl;
    }
};
void test04(){
    vector<person> vec_person;
    vec_person.push_back(person("a",1));
    vec_person.push_back(person("b",2));
    vec_person.push_back(person("c",3));
    vec_person.push_back(person("d",4));
    for_each(vec_person.begin(),vec_person.end(),mem_fun_ref(&person::print_person));

}

int main()
{
    test05();
    return 0;
}